192 research outputs found

    Ergebnisse neuerer Untersuchungen zur Würmlöß-Gliederung in Hessen

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    Die über dem letztinterglazialen Boden (Parabraunerde bzw. pseudovergleyte Parabraunerde) folgenden würmzeitlichen äolischen Sedimente können durch kennzeichnende Bodenhorizonte in 3 Abschnitte (Alt-, Mittel- und Jungwürm) gegliedert werden. Charakteristisch für das Altwürm sind Humuszonen, für das Mittelwürm neben einigen „Naßböden" braune Verlehmungszonen bis zu einer Mächtigkeit von 1,1 m und für das Jungwürm mehrere schwach ausgebildete, geringmächtige Verbraunungszonen und „Naßböden". Den wichtigsten Leithorizont des Jungwürms bildet das Kärlicher Tuffbändchen, das in jüngster Zeit auch in Nordhessen aufgefunden wurde. Abschließend wird das in Hessen aufgestellte Gliederungsschema mit den Würmlöß-Gliederungen in anderen Teilen Europas verglichen und eine Parallelisierung versucht.researc

    Investigation Into Radiation-Induced Compaction of Zerodur (trademark)

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    Zerodur is a low coefficient of thermal expansion glass-ceramic material. This property makes Zerodur an excellent material for high precision optical substrates. Functioning as a high precision optical substrate, a material must be dimensionally stable in the system operating environment. Published data indicate that Zerodur is dimensionally unstable when exposed to large doses of ionizing radiation. The dimensional instability is discussed as an increase in Zerodur density. This increase in density is described as a compaction. Experimental data showing proton-induced compaction of Zerodur is presented. The dependence of compaction on proton dose was determined to be a power law relationship

    Monitoring Agents for Assisting NASA Engineers with Shuttle Ground Processing

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    The Spaceport Processing Systems Branch at NASA Kennedy Space Center has designed, developed, and deployed a rule-based agent to monitor the Space Shuttle's ground processing telemetry stream. The NASA Engineering Shuttle Telemetry Agent increases situational awareness for system and hardware engineers during ground processing of the Shuttle's subsystems. The agent provides autonomous monitoring of the telemetry stream and automatically alerts system engineers when user defined conditions are satisfied. Efficiency and safety are improved through increased automation. Sandia National Labs' Java Expert System Shell is employed as the agent's rule engine. The shell's predicate logic lends itself well to capturing the heuristics and specifying the engineering rules within this domain. The declarative paradigm of the rule-based agent yields a highly modular and scalable design spanning multiple subsystems of the Shuttle. Several hundred monitoring rules have been written thus far with corresponding notifications sent to Shuttle engineers. This chapter discusses the rule-based telemetry agent used for Space Shuttle ground processing. We present the problem domain along with design and development considerations such as information modeling, knowledge capture, and the deployment of the product. We also present ongoing work with other condition monitoring agents

    Launch Commit Criteria Monitoring Agent

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    The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when predefined criteria have been met, identifies limit warnings and violations of launch commit criteria, aids Shuttle engineers through troubleshooting procedures, and provides additional insight to verify appropriate troubleshooting of problems by contractors. The agent has successfully detected launch commit criteria warnings and violations on a simulated playback data stream. Efficiency and safety are improved through increased automation

    Performance of wheat varieties, Oklahoma - 1980

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    The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

    HSV-2 Infection of Dendritic Cells Amplifies a Highly Susceptible HIV-1 Cell Target

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    Herpes simplex virus type 2 (HSV-2) increases the risk of HIV-1 infection and, although several reports describe the interaction between these two viruses, the exact mechanism for this increased susceptibility remains unclear. Dendritic cells (DCs) at the site of entry of HSV-2 and HIV-1 contribute to viral spread in the mucosa. Specialized DCs present in the gut-associated lymphoid tissues produce retinoic acid (RA), an important immunomodulator, able to influence HIV-1 replication and a key mediator of integrin α4β7 on lymphocytes. α4β7 can be engaged by HIV-1 on the cell-surface and CD4+ T cells expressing high levels of this integrin (α4β7high) are particularly susceptible to HIV-1 infection. Herein we provide in-vivo data in macaques showing an increased percentage of α4β7high CD4+ T cells in rectal mucosa, iliac lymph nodes and blood within 6 days of rectal exposure to live (n = 11), but not UV-treated (n = 8), HSV-2. We found that CD11c+ DCs are a major target of HSV-2 infection in in-vitro exposed PBMCs. We determined that immature monocyte-derived DCs (moDCs) express aldehyde dehydrogenase ALDH1A1, an enzyme essential for RA production, which increases upon HSV-2 infection. Moreover, HSV-2-infected moDCs significantly increase α4β7 expression on CD4+ T lymphocytes and HIV-1 infection in DC-T cell mixtures in a RA-dependent manner. Thus, we propose that HSV-2 modulates its microenviroment, influencing DC function, increasing RA production capability and amplifying a α4β7highCD4+ T cells. These factors may play a role in increasing the susceptibility to HIV-1

    Between Commerce and Empire: David Hume, Colonial Slavery, and Commercial Incivility

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    Eighteenth-century Enlightenment thought has recently been reclaimed as a robust, albeit short-lived, cosmopolitan critique of European imperialism. This essay complicates this interpretation through a study of David Hume’s reflections on commerce, empire and slavery. I argue that while Hume condemned the colonial system of monopoly, war and conquest, his strictures against empire did not extend to colonial slavery in the Atlantic. This was because colonial slavery represented a manifestly uncivil institution when judged by enlightened metropolitan sensibilities, yet also a decisively commercial institution pivotal to the eighteenth-century global economy. Confronted by the paradoxical ‘commercial incivility’ of modern slavery, Hume opted for disavowing the link between slavery and commerce, and confined his criticism of slavery to its ancient, feudal and Asiatic incarnations. I contend that Hume’s disavowal of the commercial barbarism of the Atlantic economy is part of a broader ideological effort to separate the idea of commerce from its imperial origins and posit it as the liberal antithesis of empire. The implications of analysis, I conclude, go beyond the eighteenth-century debates over commerce and empire, and more generally pertain to the contradictory entwinement of liberalism and capitalism
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